In the knitting of circular knit pile fabric, it is the normal practice to knit a single pile yarn and a body or ground yarn together in plated relationship at every knitting station while forming pile or terry loops of the pile yarn. The pile or terry loops are formed by advancing sinkers between adjacent cylinder needles so that the pile or terry loops are formed over the upper nibs of the sinkers while the body yarn stitch loops are drawn over the lower stitch drawing ledge of the sinkers. After the terry loops are formed in this manner, the fabric is sheared to produce pile extending outwardly from one surface of the knit fabric. However, the length of the pile or terry loops formed in this manner is limited by the height of the upper nib of the sinkers. This knit fabric is rather heavy and bulky since the pile yarn is knit in plated relationship with the body of ground yarn in the needle loops and it is not possible to easily change the height of the pile or terry loops being formed. Also, the plating of the pile yarn with the body yarn may not be accurately controlled so that portions of the pile yarn may be visible and may extend inwardly on the inside or back of the fabric.
Recognizing these deficiencies of pile fabric formed with the use of sinkers, the Mishcon U.S. Pat. No. 2,796,751 discloses the formation of a circular knit pile fabric by employing hooked loop jacks in the dial of the circular knitting machine so that the height of the pile or terry loops can be varied by merely varying the amount the hooked loop jacks are withdrawn or retracted into the dial, after picking up the pile yarn therein. This patent also discloses eliminating the problem of plating of the pile yarn with the body yarn by inlaying the pile yarn in the knit fabric formed by the body yarn. However, this patent discloses utilizing half the number of hooked loop jacks as the number of cylinder needles and forming plain jersey stitch loops of body yarn on alternate cylinder needles while forming the pile or terry loops of the pile yarn on every hooked loop jack at each knitting station. The pile fabric produced in accordance with this patent thus includes a pile or terry loop extending inwardly and between every wale of the plain jersey stitch loops of each course of the body yarn.
U.S. Pat. No. 5,016,450, dated May 21, 1991, a circular knit pile fabric and method is disclosed in which the successive courses of body yarn include pile yarn inlaid in every other wale while pile or terry loops extend inwardly and across the remaining wales, and wherein the pile or terry loops in alternating single courses are staggered walewise relative to the pile or terry loops in intervening single courses. The disclosed method of knitting the circular knit pile fabric of my copending application is carried out on a circular knitting machine including a plurality of circularly arranged cylinder needles movable vertically between latch clearing and stitch drawing positions. A single dial hook element is supported in each groove of the dial and the number of dial hook elements is equal to the number of cylinder needles.
The pile fabric produced in accordance with my copending application does permit the pile loops of the pile fabric to be formed of any desired length and the length of the pile loops is not determined by the height of the various ledges of the sinkers. However, the pile fabric produced in accordance with my copending application is limited to a single color of pile yarn in each course of the body or ground yarn.